Conductive elastomeric foam materials and methods of use

Abstract

Described herein are conductive elastomeric foam materials and methods of making and using the same. The conductive elastomeric foam materials include a polymeric matrix, one or more conductive fillers, and one or more foaming agents. The polymeric matrix can include a thermoset polymer or a thermoplastic polymer. Also described herein are methods of making conductive elastomeric foam materials. Further described herein are molded products including the conductive elastomeric foam materials as described herein and wearable devices including the molded products.

What is claimed is: 
     
         1 . A conductive elastomeric foam material, comprising:
 a polymeric matrix;   one or more conductive fillers; and   one or more foaming agents.   
     
     
         2 . The conductive elastomeric foam material of  claim 1 , wherein the polymeric matrix comprises a thermoset polymer. 
     
     
         3 . The conductive elastomeric foam material of  claim 2 , wherein the thermoset polymer is selected from the group consisting of a silicone, a urethane, a urethane acrylate, an acrylate, a methacrylate, a polysulfide, a polythioether, an epoxy, a phenolic resin, and combinations thereof. 
     
     
         4 . The conductive elastomeric foam material of  claim 1 , wherein the polymeric matrix comprises a thermoplastic polymer. 
     
     
         5 . The conductive elastomeric foam material of  claim 4 , wherein the thermoplastic polymer is selected from the group consisting of styrenic block copolymers, thermoplastic polyurethanes, polyethylenes, polypropylenes, polystyrenes, polyesters, polyamides, polyimides, polyphenylene sulfides, polyvinyl alcohols, polylactic acids, and thermoplastic silicones. 
     
     
         6 . The conductive elastomeric foam material of  claim 1 , wherein the one or more conductive fillers comprises a 1D filler, a 2D filler, or a combination thereof. 
     
     
         7 . The conductive elastomeric foam material of  claim 1 , wherein the one or more foaming agents comprises an inorganic foaming agent, an organic foaming agent, or a microbead. 
     
     
         8 . A method of making a conductive elastomeric foam material according to  claim 1 , comprising:
 mixing a polymeric matrix, one or more conductive fillers, and one or more foaming agents to form a foamable conductive elastomeric material; and   applying a foaming process to the foamable conductive elastomeric material to form a conductive elastomeric foam material having a plurality of pores.   
     
     
         9 . A molded product, comprising a conductive elastomeric foam material according to  claim 1 . 
     
     
         10 . The molded product of  claim 9 , wherein the molded product comprises a cylindrical shape having a diameter from 1 mm to 10 mm. 
     
     
         11 . The molded product of  claim 9 , wherein the molded product is a flat shape, a microneedle, a fuzzy structure, a dome shape, a hollow structure, or a cone shape. 
     
     
         12 . The molded product of  claim 9 , wherein at least one surface of the molded product is surface coated with a coating material or a plurality of pores within the conductive elastomeric foam material is coated with a coating material. 
     
     
         13 . The molded product of  claim 12 , wherein the coating material is selected from the group consisting of poly(3,4-ethylenedioxythiophene) polystyrene sulfonate (PEDOT:PSS), a sulfonated tetrafluoroethylene based fluoropolymer-copolymer, a polymer binder, polyaniline, polypyrrole, silver nanowires (AgNW), gold nanowires (AuNW), liquid metal, and gold. 
     
     
         14 . The molded product of  claim 9 , wherein the molded product exhibits a bulk conductivity of 10 Ohm-cm or lower. 
     
     
         15 . The molded product of  claim 9 , wherein the molded product exhibits a tensile strength of 0.5 MPa or greater. 
     
     
         16 . The molded product of  claim 9 , wherein the molded product exhibits a modulus of 5 MPa or lower. 
     
     
         17 . The molded product of  claim 9 , wherein the molded product exhibits a hardness of 70 Shore A or lower. 
     
     
         18 . The molded product of  claim 9 , wherein the molded product exhibits a compression stroke of at least 50%. 
     
     
         19 . A wearable device, comprising a molded product of  claim 9  integrated into the wearable device. 
     
     
         20 . The wearable device of  claim 19 , wherein the wearable device is a wristband or a monolithic conductive band.